Selective reference plane bridge(s) on folded package

Abstract

An apparatus including a substrate having dimensions suitable as a support circuit for at least one integrated circuit, the substrate comprising a laterally extending plication region defining first and second longitudinal portions; a plurality of conductive traces distributed in a first distribution plane of the substrate and extending transversely through the plication region; a first and second layers of conductive material in a second distribution plane of the first portion and second portion, respectively, of the substrate; at least one conductive bridge extending transversely through less than the entire plication region in the second distribution plane and coupled to the first continuous layer and to the second continuous layer; and at least one externally accessible contact point coupled to at least one of the first and second layers. A method of forming a support circuit and a system including a package.

1. An apparatus comprising:
 a substrate having dimensions suitable as a support circuit for at least one integrated circuit and a thickness sufficient to accommodate at least two distribution planes, the substrate comprising a laterally extending plication region defining a first longitudinal portion and a second longitudinal portion; 
 a plurality of conductive traces distributed in a first distribution plane of the substrate and extending transversely through the plication region between the first portion and the second portion; 
 a first continuous layer of conductive material in a different second distribution plane of the first portion of the substrate and a second continuous layer of conductive material in the second distribution plane of the second portion of the substrate; 
 at least one conductive bridge extending transversely through the plication region in the second distribution plane and coupled to the first continuous layer and to the second continuous layer, the bridge having a lateral width less than a lateral width of the first continuous layer and a lateral width of the second continuous layer, the bridge comprising a lateral width through the plication region spatially aligned in a lateral dimension to an area of the first distribution plane through which less than an entire portion of the plurality of conductive traces traverse the plication region; and 
 at least one externally accessible contact point coupled to at least one of the first continuous layer and the second continuous layer. 
 
   
   
     2. The apparatus of  claim 1 , wherein the plurality of conductive traces can be classified as ones sensitive to impedance variations and ones insensitive to impedance variations for a particular application and the ones of the less than the entire portion of the plurality of conductive traces comprise ones sensitive to impedance variations. 
   
   
     3. The apparatus of  claim 1 , comprising a plurality of conductive bridge each comprising a lateral width and laterally spaced from one another and spatially aligned in a lateral dimension to respective areas of the first distribution plane through which respective portions of the plurality of conductive traces transverse the plication region. 
   
   
     4. The apparatus of  claim 1 , further comprising a plurality of externally accessible contact points on the first portion and coupled to the plurality of conductive traces and configured to route signals between an integrated circuit device on the first portion through respective ones of the plurality of conductive traces. 
   
   
     5. The apparatus of  claim 1 , wherein the substrate comprises a flexible material. 
   
   
     6. The apparatus of  claim 5 , wherein the flexible material comprises a polyimide. 
   
   
     7. An apparatus comprising:
 an integrated circuit comprising a plurality of devices and externally accessible signal circuitry; and 
 a substrate having dimensions suitable as a support circuit for at least the integrated circuit and a thickness sufficient to accommodate at least two distribution planes, the substrate comprising:
 a laterally extending plication region defining a first longitudinal portion and a second longitudinal portion, 
 a plurality of conductive traces distributed in a first distribution plane of the substrate and coupled to the integrated circuit and extending transversely through the plication region between the first longitudinal portion and the second longitudinal portion, 
 a first continuous layer of conductive material in a different second distribution plane of the first portion of the substrate and a second continuous layer of conductive material in the second distribution plane of the second portion of the substrate, and 
 at least one conductive bridge having a lateral width less than a lateral width of the first continuous layer and a lateral width of the second continuous layer and extending transversely through the plication region in the second distribution plane and coupled to the first continuous layer and to the second continuous layer, wherein the bridge comprises a lateral width through the plication region spatially aligned in a lateral dimension to an area of the first distribution plane through which less than an entire portion of the plurality of conductive traces traverse the plication region. 
 
 
   
   
     8. The apparatus of  claim 7 , wherein the substrate further comprises at least one externally accessible contact point coupled to at least one of the first continuous layer and the second continuous layer. 
   
   
     9. The apparatus of  claim 7 , wherein the substrate is coupled to the integrated circuit through a first plurality of externally accessible contact points and the substrate further comprises a second different plurality of externally accessible contact points coupled to the conductive traces. 
   
   
     10. The apparatus of  claim 7 , wherein the integrated circuit comprises a first integrated circuit coupled to the first portion of the substrate and the apparatus comprises a second integrated circuit coupled to the second portion of the substrate. 
   
   
     11. An apparatus comprising:
 a housing; 
 a printed circuit board coupled to and disposed within the housing; 
 a package coupled to the printed circuit board, the package comprising an integrated circuit and a substrate, the substrate comprising:
 a first longitudinal portion and a second longitudinal portion defined by a plication in the substrate, 
 a plurality of conductive traces distributed in a first distribution plane of the substrate and coupled to the integrated circuit and extending between the first portion and the second portion, 
 a first continuous layer of conductive material in a different second distribution plane of the first portion of the substrate and a second continuous layer of conductive material in the second distribution plane of the second portion of the substrate, 
 at least one conductive bridge in the second distribution plane extending transversely through the entire plication and coupled to the first continuous layer and to the second continuous layer wherein the bridge comprises a lateral width through the plication region spatially aligned in a lateral dimension to an area of the first distribution plane through which less than an entire portion of the plurality of conductive traces traverse the plication region, and 
 a contact point coupled to at least one of the first continuous layer and the second continuous layer and coupled to a reference point of the printed circuit board; and 
 
 a memory chip coupled to the printed circuit board. 
 
   
   
     12. The apparatus of  claim 11 , wherein the reference point of the printed circuit board is a ground reference point. 
   
   
     13. A method comprising:
 forming a substrate having dimensions of a support circuit for at least one integrated circuit, the substrate comprising a laterally extending plication region defining a first longitudinal portion and a second longitudinal portion; 
 patterning a plurality of conductive traces on a first surface of the substrate, a portion of the plurality of conductive traces extending transversely through the plication region between the first portion and the second portion; 
 forming a continuous layer of conductive material on a second surface of the substrate opposite the first surface in a second distribution plane of the first portion of the substrate and a second continuous layer of conductive material in the second distribution plane of the second portion of the substrate; 
 patterning the continuous layer into a first continuous layer portion on the first longitudinal portion of the substrate, a second continuous layer on the second longitudinal portion, and at least one conductive bridge extending transversely through less than the entire plication region and coupled to the first continuous layer and to the second continuous layer; and forming at least one externally accessible contact point to at least one of the first continuous layer and the second continuous layer. 
 
   
   
     14. The method of  claim 13 , wherein patterning a plurality of conductive traces comprises patterning ones sensitive to impedance variations and ones insensitive to impedance variations for a particular application and the ones of the plurality of conductive traces that are sensitive to impedance variations are patterned to be spatially aligned with the at least one conductive bridge. 
   
   
     15. The method of  claim 13 , wherein patterning the continuous layer comprises patterning a plurality of bridges spaced from one another and each extending transversely through less than the entire plication region.